My overall career goal is to understand if hearing loss is a remediable risk factor for AD and to become a leader in aging research with my specialty of otolaryngology. Age-related hearing loss and Alzheimer's disease dementia (AD) are distinct neurologic conditions that affect millions of older adults worldwide. Age- related hearing loss is the third most common, chronic condition among older adults. We have identified hearing loss as a risk factor for dementia through epidemiologic studies. The mechanisms of how age-related hearing loss causes AD or whether an auditory intervention decreases the risk for AD, however, are unknown. Moreover, for patients on the extreme end of the hearing loss spectrum with severe-profound hearing loss, it is unknown how an intervention to restore hearing via cochlear implantation will have any cognitive benefit or protective cognitive effect. We hypothesize that restoring hearing via cochlear implantation in older adults with severe-to-profound sensorineural hearing loss will improve cognitive function. We also hypothesize that cochlear implantation and the expected hearing benefit that results will also have an impact on the quality of life of the implant recipients as well as their communication partners or caregivers. We will employ an innovative application of neuropsychiatric testing and a novel cognitive battery designed for a population of individuals with severe-profound hearing loss to understand the potential biological association of age-related hearing loss and cognitive decline. While cochlear implantation is the standard of care to restore hearing for older adults with profound hearing loss, the proposed research will shift traditional paradigms on how we measure outcomes in older cochlear implant recipients by introducing cognitive evaluation as part of the pre- and post-operative test battery. We will also employ validated quality of life surveys to assess how this population and their caregivers are affected by cochlear implantation. Another innovation of this project is the unique training program that is proposed for the principal investigator. The project brings together mentors from diverse fields ? cognitive neurology, geriatric medicine, neurophysiology, and otolaryngology ? to create a specialized training experience in aging research. This professional development plan will allow the principal investigator to become a leader in otolaryngology, particularly in the cognitive impact of age-related hearing loss and aging research. The training program that is offered through the GEMSSTAR award funding period will equip the principal investigator with the ability to answer the question of whether hearing loss is a remedial risk factor to dementia in older adults. The significance of this work is to improve the quality of life and prevent cognitive decline in older adults with hearing loss. Completion of this study will help develop expertise in neuroimaging, psychosocial evaluation, and clinical research in older adults with hearing loss. This expertise will benefit a large population of hearing impaired older adults as it is applied in future studies.